1. Field of the Invention
The present invention relates to space-related communications and more specifically to communicating telemetry data in a standardized way between a ground station and a control center.
2. Introduction
To monitor the health and safety of spacecraft, a spacecraft must transmit spacecraft telemetry data to a ground station (such as a large antenna or a radio dish), a mission control center (such as those maintained by NASA, ESA, and FKA) must receive that telemetry data from the ground station, and the mission control center must be able to send commands and/or other information to the spacecraft through the ground station. The ground station and mission control center are often far from each other for logistical and other reasons. The criteria for an ideal ground station site, such as lack of interference and favorable weather, usually place ground stations in remote locations like New Norcia, Australia, and Kaena Point, Hi. Housing, education, and other human-resource related needs of the extensive staff of a mission control center make such remote locations impractical for mission control centers. Thus, the current practice is to place the ground station and mission control center in respectively well-suited locations and establish a communication link between the two.
In the past, each space mission implemented custom data communication designs and protocols to communicate between the spacecraft, ground station, and mission control center. As the number of space missions and spacecraft rose, so did the number of incompatible communication protocols. Communication required numerous translation and interpretation modules to bridge these incompatibilities. These extra translation and interpretation modules are not perfect and can introduce delays or errors into communication with spacecraft. The Consultative Committee for Space Data Systems (CCSDS) developed Space Link Extension (SLE) services to standardize the interfaces and enable ground stations and mission control centers across different national and international space agencies to interoperate without the need for ad hoc custom data communications designs.
Software libraries exist which implement SLE, but users must access them through an overly cumbersome and complex interface. For example, the existing SLE Return Channel Frames libraries define over 1,000 interface routines. Accordingly, what is needed in the art is a simplified, streamlined, unified way to coordinate communication between spacecraft, ground stations, and control centers.